JPS6340864A - Apparatus for detecting rotational speed - Google Patents

Abstract

PURPOSE:To enhance the accuracy and response of measurement, by providing a plurality of signal detection means. CONSTITUTION:Magnetic poles are formed to the signal parts 7 provided to the entire periphery of a rotary signal device 1 at the equally divided positions thereof to generate magnetic signals due to magnetic fields. A signal detection means 2 is constituted of a large number of sensors, such as a first sensor 2a, a second sensor 2b,v arranged at a definite interval and outputs the signals from the signal parts 1 to a detection/control means to operationally calculate a rotational speed. The times of the sensors passing through a large number of magnetic pole sections can be respectively detected at the almost same time independently and separately by the sensors. That is, since data can be taken in from the large number of the magnetic pole sections within a short time, the enhancement of the accuracy and response of measurement is achieved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotational speed detection device that is attached to an axle or the like on which a wheel is rotated and is capable of calculating and detecting the rotational speed of the rotating axle or the like. be.

[Conventional technology]

Various driving systems have been proposed that can constantly check the wheel speed of vehicles such as automobiles and two-wheeled motorbikes and aim for comfortable and safe operation of the vehicle.
A rotation signal generator 101 integrally attached to the rotating shaft 100 side that rotates the rotation signal generator 101, a sensor 102 such as a magnetoresistive element provided on the vehicle body (concave road) side near the rotation signal generator 101, and a control section. (concave road), etc.

The rotation signal generator 101 usually has an annular shape, and magnetic poles 1 are magnetized at regular intervals along the outer surface of the circumference.
03 plastic magnet. By the way, the rotation speed detection device with such a configuration is
The passage of each magnetic pole 102 is detected based on electrical changes in the sensor 102 due to changes in magnetic flux density when each magnetic pole 103 passes through the previous sensor 102 by 1 Irl, and each magnetic pole known in advance is detected. From the distance d between them and the time t taken for each magnetic pole 102 to pass, the rotational speed V (here, it refers to the circumferential speed of the rotational speed generator) every time each magnetic pole 102 passes the sensor is calculated by the following formula. Calculation detection is based on the % expression %.

[Problem to be solved]

By the way, in a rotation speed detection device with such a configuration, the rotation signal! The accuracy of the distance dimension of the magnetic pole section formed in 5101 has directly influenced the accuracy of the rotational speed, and as a result, even if the rotational speed were constant, the distance dimension of the magnetic pole section that happened to pass through the sensor 102 at that time would be short. In some cases, there is a bottom where the rotational speed is detected as a value larger than the magnetic property.

Therefore, in order to calculate a more accurate rotation speed by detecting the rotation speed from a large number of magnetic pole sections, for example,
It has been proposed to take in the 1lfj elapsed time between each magnetic pole continuously from a plurality of locations and average the data. However, when using this method to improve the rotation speed structure, quality, and high loading capacity, the time required to acquire data increases significantly, resulting in poor responsiveness. It is practically impossible to use it in a safe driving system where short-time operation can help avoid accidents.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional drawbacks, it is an object of the present invention to provide a rotation speed detection device that has good responsiveness and is capable of detecting the rotation speed of a rotation signal with high accuracy. It is.

[Means for solving problems]

That is, the present invention includes a rotation signal device in which signal portions are formed at regular intervals along the outer circumferential direction, and signal portion detection means for detecting a signal from the signal portion, and the rotation speed of the rotation signal device is A rotational speed detection device that calculates and detects a rotational speed, wherein the signal section detection means independently and independently receives signals from a plurality of signal sections.
The signal detection means is composed of a plurality of sensors so as to detect the signals separately, and the control means is provided for calculating and detecting the rotation speed of the rotation signal device based on the detection signals output from the sensors. It is something.

[Effect]

In the rotational speed detection device of the present invention, each of the plurality of sensors is capable of independently and separately detecting the transit time at which a plurality of magnetic pole sections pass through each sensor at approximately the same time. In other words, data from between the plurality of magnetic poles can be taken in in a short time, making it possible to detect the rotational speed with high precision and improving responsiveness.

〔Example〕

An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show a rotation speed detection device according to the present invention, which includes a rotation signal device 1, a signal section detection means 2 consisting of a plurality of sensors,
It is composed of a control means 3. In addition, the reference numeral 4 in the figure is a rotating shaft that is integrated with the rotation signal device 1 to rotate the wheels (concave road) and the like.

The rotation signal device 1 is formed into a substantially annular shape using a plastic magnet or the like, and convex signal portions 7 are provided on the edge side of the outer peripheral surface at positions dividing the entire circumference into n equal parts. A magnetic pole is formed in each of these signal sections 7, and the rotational speed is detected by a magnetic signal generated by a magnetic field generated from the magnetic pole. Note that as the signal at this frequency division point, it is also possible to use an optical signal or the like printed with a mark, such as black, in addition to the previous magnetic pole.

The signal portion detection means 2 detects a signal from the outside 7 when the frequency division point 5 passes directly below the signal portion detection means 2, etc., and outputs a detection signal to the control means 3 side. In this embodiment, a sensor composed of a bridge circuit or the like is attached to the vehicle body (concave road) side in order to electrically detect changes in magnetic flux density generated from the frequency division point 5 side. The sensors of this embodiment include a first sensor 2a, a second sensor 2b, and a third sensor arranged at a constant interval from each other.
The number of sensors 2c is J, +7 from three, but the number of sensors is not particularly limited to this, and if possible, more data can be obtained by arranging a large number of sensors. The rotation speed can be detected with high precision.

The control means 3 is for calculating the rotation speed of the rotation signal device 1 based on the detection signals output from the first sensor 2a to the third sensor 2c, and is configured to calculate the rotation speed of the rotation signal device 1 based on the detection signals output from the first sensor 2a to the third sensor 2c. It is configured. The time measurement unit 5 is for calculating the transit time specific to the signal section S passing through the first sensor 2a to the third sensor 2c, and is composed of a counter consisting of a flip-flop or the like, and the input side is They are connected to the output sides of the first sensor 2a to third sensor 2c, respectively, and the output side is connected to the input side of the calculation section 6. The calculation unit 6 is for calculating the average value of the passing time between each dividing point diagram S, which is the data for each sensor obtained by the calculation processing in the time measurement unit 5. The system consists of a microprocessor, etc.

Therefore, according to the rotational speed detection device according to this embodiment, as shown in FIG.
When the passage of the @th frequency division point is detected and a detection signal is output, the first sensor 2a and the third sensor 2c are activated at the 11th point and the 101st point, respectively, at approximately the same time. A detection signal is output by detecting passage of the frequency dividing point.

Then, after passing the L2 time, the second sensor 2b first detects the passing of the +1st frequency division point and outputs the next detection signal, and then the third sensor 2c detects the passing of the +1st frequency division point. The first sensor 2a detects the passage of the point, and lastly, at time T2, which is t4 hours after time T1, the first sensor 2a detects the passage of the th frequency dividing point and outputs a detection signal.

In this way, the first sensor 2a, the second sensor 2b, and the third sensor 2c each independently and separately, and each sensor detects passage between one dividing point diagram at approximately the same time, that is, T4 time. It is possible to detect the transit time between the three frequency division point diagrams in a short time that is almost the same as that required for the calculation.

〔effect〕

As explained above, according to the rotational speed detection device according to the present invention, the time required for detecting the passing time of one section by the signal section detection means consisting of a plurality of sensors is approximately the same or close to that time. It is possible to detect as data the passing time of the same number of sections as the sensors that constitute the signal part detection means, which allows more accurate rotational speed to be calculated more quickly, and the response Therefore, it is possible to provide a rotation speed detection device with good performance and high accuracy.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the main parts of the rotation speed detection device according to the present invention, FIG. 2 is a block diagram showing the configuration of the rotation speed detection device according to the invention, and FIG. 3 is a signal section detection diagram according to the invention. FIG. 2 and FIG. 4 are explanatory diagrams showing a conventional rotational speed detection device. 7...Signal section, ■...Rotation signal device, 2...Signal section detection means, 3...
...control means. Applicant: NEC Home Electronics Co., Ltd.

Claims (1)

[Claims] 1. It comprises a rotation signal device in which signal sections are formed at regular intervals along the outer circumferential direction, and signal section detection means for detecting signals from the signal section, and calculates and calculates the rotation speed of the rotation signal device.
A rotational speed detection device for detecting a rotational speed, wherein the signal detection means is composed of a plurality of sensors so that the signal detection means detects signals from a plurality of signal sections independently and separately, and the signal detection means is composed of a plurality of sensors. 1. A rotation speed detection device comprising a control means for calculating and detecting a rotation speed of a rotation signal device based on a detection signal output from a sensor.